Despite significant gains achieved by public education campaigns in past decades, many people still underestimate the risks of tobacco use. The situation is compounded by aggressive marketing of new and alternative tobacco products, such as snus, dissolvables, and electronic cigarettes. A timely public health response comprising more nuanced communication about health effects of tobacco products and regulation of new tobacco products is needed. Although new tobacco products have been marketed in the US since 2006, research examining effective counter-messages has been virtually nonexistent. The proposed project will determine effective ways to communicate harm of tobacco products by pursuing three Specific Aims: (1) Identify key features (e.g., naming specific diseases, depicting affected body parts, or listing harmful chemicals) of informational and emotional anti-tobacco messages. (2) Compare the effects of informational messages and those that combine information with emotional appeals on perceptions of harm of tobacco products, intentions to use tobacco products, and attitudes towards regulation of these products. (3) Determine how communication about cigarettes vs. novel tobacco products distinctly impacts message processing and responses to anti-tobacco messages among different subpopulations - current smokers, former smokers, and non-smokers. Work on Aim 1 will happen during the K99 phase and the key features of emotional and informational messages determined during this stage will inform development of anti-tobacco messages for testing in Aim 2 (R00 phase). During the R00 phase, I will run a series of four studies to test hypotheses of Aim 2 with different message topics (such as addiction, harmful constituents of tobacco products, or second-hand smoke), with various tobacco products (cigarettes and novel tobacco products), and in different populations (current and former smokers and non-smokers). The data from these studies will be pooled to accomplish Aim 3 through integrative data analysis, which will also occur in the R00 stage. In evaluating effects of anti-tobacco messages this project will go beyond the image/text dichotomy that dominated past research on cigarette warning labels. The proposed studies will be guided by the new conceptual model of processing and outcomes of anti-tobacco messages and will examine both desirable responses to the message and undesirable responses, such as message avoidance or reactance, another area of research on anti-tobacco messages that has received only limited empirical attention. This proposal will enable me to expand my training in tobacco control, regulatory science, advanced statistical methods, and behavioral interventions under the mentorship of a multidisciplinary team of experts in tobacco control, and provide critical preliminary data for me to launch my independent research career. This research is directly relevant to the development of new effective tools to counteract the increased promotion of novel tobacco products and will inform the FDA's policymaking and educational efforts on new and established tobacco products, including graphic warning labels.